Systems are known in the art, which are designed for cooling objects located in a low-pressure environment. For example, during space exploration, it is important to control the temperature of the surface and the body of the space vehicle in order to dissipate the waste heat generated by electronics of the space vehicle, and any heat absorbed by the vehicle shell due to external radiation emanated from the sun. Likewise, it is important to control the temperature of a spacesuit to dissipate the metabolic heat of the suit inhabitant.
For example, U.S. Pat. No. 3,212,286 describes a spacesuit having a thermally conductive wall with a plurality of porous metal block evaporators distributed over and in good thermal contact with the exterior of the wall. The metal blocks act as constant temperature heat sinks, dissipating into space the heat transferred to them by the suit wall.
The evaporators are supplied by a water evaporant from a reservoir within the spacesuit, the water being under the atmospheric pressure of the suit. On first entering the evaporator, the water does not immediately freeze, due to its own vapor pressure, and wetting of the interior surfaces of the evaporator block occurs. Then, the water freezes and then sublimes to remove heat from the block. As sublimation proceeds, passages open to admit more water, thus sustaining the cooling process.
U.S. Pat. No. 3,613,775 describes a cooling system for removing metabolic heat in a life support system used in space activity. In operation, coolant passes through a sublimator which also includes a pump and a coolant garment. A separate water storage container provides feedwater to the sublimator where it is sublimated along a surface thermally connected to a heat exchange element through which the coolant flows.
U.S. Pat. No. 5,092,129 describes an apparatus for removing heat energy of a cooling medium passing from a spacesuit liquid cooling garment. The apparatus includes a heat sink assembly for absorbing and rejecting the heat energy and a heat transfer means for transferring the heat energy of the cooling medium to the heat sink assembly. The heat transfer means, which is comprised of an array of thermoelectric modules, regulates the quantity of heat energy transferred from the cooling medium to the heat sink assembly. The heat sink assembly includes a material that isothermally changes phase while absorbing heat energy.